There are some differences because your nutritional data is computed differently than ours (the info on the products). Each country's WW program is tailored to the foods available and the customs of the country. Run it through the WW calculator on the British site.
I have never had red velvet cake...tho I hear its quite delicious...I have no desire (imagine that) to eat it. Nor have I ever had a Twinkie. Seriously. Put ravioli in front of me tho, that's a different story altogether.